The sign for "hurt" is made by extending the index fingers of both hands. Bring the fingers toward each other twice using a jabbing movement.
A variation of this sign is to do a twisting movement as you bring the tips of the index fingers toward each other. The right hand twists one way and the left hand twists the other.
Note: Both versions of the sign for "HURT / PAIN" can be done on or near the part of the body that is feeling pain. For example if you have a toothache, you can indicate that in one sign by doing the sign "hurt" near the side of your jaw. If you have a headache, you can indicate it by signing "hurt" near your forehead. Personally, for a general headache or toothache I use the double jab movement. But if it is a "killer" headache I do a single strong twist of each hand simultaneously.